Subtrochanteric osteotomy and reconstruction with total hip arthroplasty
Developmental dysplasia of hip is characterized with a shallow hip socket, various degree of subluxation or even dislocation of the femoral head, and risks of early osteoarthritic change. For a more severe type of hip dysplasia – high-grade developmental dysplasia of hip, can lead to limping, hip pain, leg length discrepancy (if unilateral) and cosmetic concerns.
Reconstruction with total hip arthroplasty alone might not be easy as usual cases. Special osteotomy techniques and methods to protect sciatic nerve are certainly necessary to ensure the success of this surgery.
Developmental dysplasia of hip is a disease with a wide spectrum, from mild, early osteoarthritic change of hip joint to hip dislocation. For a more severe form of hip dysplasia (Crowe type III or IV, high-grade, high-riding developmental dysplasia of hip), reconstruction with total hip arthroplasty in combination with femoral osteotomy and methods to protect sciatic nerve is the mainstay of treatment.
Patients usually complain about limping, leg length discrepancy, and hip pain because of a dislocated hip with malfunctioning abductor muscle. This surgery can effectively lengthen the affected limb, improve the performance of abductor muscle and relieve hip pain.
The surgery takes approximately two hours. Wound size is about 20cm, along the lateral side of the hip and thigh.
Usually, the affected leg is shortened more than 5-7 cm. But the sciatic nerve can only usually tolerate approximately 4cm of lengthening. Otherwise, too much increased tension might lead to sciatic nerve palsy. Therefore, we have to do femoral osteotomy (subtrochanteric osteotomy) to match the limb lengthening to 4cm. In other words, we have to cut approximately 2cm (6 - 4 =2) of femoral bone segment to match this amount of correction.
In addition, we have to test sciatic nerve function during surgery after correction to make sure the correction is not too much. Therefore, the patient will receive general anesthesia and be “wake-up” without a sense of pain during surgery by professional anesthesiologists. They will ask the patient to extend the big toe and dorsi-flex the ankle, if ok, the patient will be put into a sleep again right away.
Total hip arthroplasty procedure is quite similar to that of our routine methods. An additional plate is required for femoral bone fixation at osteotomy site.
After surgery, partial weight-bearing program is allowed with the use of a cane or crutches for 3 months. After 3 months, with signs of bone union on the femoral osteotomy site, patients can walk without weight-bearing restrictions.
Features of Taipei Veterans General Hospital
- Subtrochanteric osteotomy technique
Accurate osteotomy techniques can lengthen the affected leg to compensate excessive leg length discrepancy, improve abductor muscle performance and correct limping.
- Intra-operative wake-up test
Sciatic nerve is effectively protected using this method. We have an international publication describing this method.
The procedure cost is around 600,000 NTD, depends on the actual medical expenses.